The Experts below are selected from a list of 19230 Experts worldwide ranked by ideXlab platform
Emo Chiellini - One of the best experts on this subject based on the ideXlab platform.
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oxidation and biodegradation of polyethylene films containing pro oxidant additives synergistic effects of sunlight exposure thermal aging and fungal biodegradation
Polymer Degradation and Stability, 2010Co-Authors: Andrea Corti, Sudhakar Muniyasamy, Manuele Vitali, Syed H Imam, Emo ChielliniAbstract:Abstract Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear Low Density poly(ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days during the summer months folLowed by their incubation with fungal strains previously isolated from the soil based on the ability to grow on the oxidized PE-LLD as a sole carbon source. Some films were also thermally aged at temperatures ranging between 45°C and 65 °C, either before or after fungal degradation. Films with pro-oxidant additives exhibited a higher level of oxidation as revealed by increase in their carbonyl index (CO i ). In addition to increase in the CO i , films showed a slight increase in crystallinity and melting temperature ( T m ), considerably Lower onset degradation temperatures, and a concomitant increase in the % weight of the residues. The level of oxidation observed in thermally aged films was directly proportional to the aging temperature. The PE-LLD films with pro-oxidant exposed to sunlight folLowed by thermal aging showed even higher rate and extent of oxidation when subsequently subjected to fungal biodegradation. The higher oxidation rate also correlated well with the CO 2 production in the fungal biodegradation tests. Similar films oxidized and aged but not exposed to fungal biodegradation showed much less degradation. Microscopic examination showed a profuse growth and colonization of fungal mycelia on the oxidized films by one strain, while another spore-producing strain grew around the film edges. Data presented here suggest that abiotic oxidation of polymer's carbon backbone produced metabolites which supported metabolic activities in fungal cells leading to further biotically-mediated polymer degradation. Thus, a combined impact of abiotic and biotic factors promoted the oxidation/biodegradation of PE-LLD films containing pro-oxidants.
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oxidation and biodegradation of polyethylene films containing pro oxidant additives synergistic effects of sunlight exposure thermal aging and fungal biodegradation
Polymer Degradation and Stability, 2010Co-Authors: Andrea Corti, Sudhakar Muniyasamy, Manuele Vitali, Syed H Imam, Emo ChielliniAbstract:Abstract Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear Low Density poly(ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days during the summer months folLowed by their incubation with fungal strains previously isolated from the soil based on the ability to grow on the oxidized PE-LLD as a sole carbon source. Some films were also thermally aged at temperatures ranging between 45°C and 65 °C, either before or after fungal degradation. Films with pro-oxidant additives exhibited a higher level of oxidation as revealed by increase in their carbonyl index (CO i ). In addition to increase in the CO i , films showed a slight increase in crystallinity and melting temperature ( T m ), considerably Lower onset degradation temperatures, and a concomitant increase in the % weight of the residues. The level of oxidation observed in thermally aged films was directly proportional to the aging temperature. The PE-LLD films with pro-oxidant exposed to sunlight folLowed by thermal aging showed even higher rate and extent of oxidation when subsequently subjected to fungal biodegradation. The higher oxidation rate also correlated well with the CO 2 production in the fungal biodegradation tests. Similar films oxidized and aged but not exposed to fungal biodegradation showed much less degradation. Microscopic examination showed a profuse growth and colonization of fungal mycelia on the oxidized films by one strain, while another spore-producing strain grew around the film edges. Data presented here suggest that abiotic oxidation of polymer's carbon backbone produced metabolites which supported metabolic activities in fungal cells leading to further biotically-mediated polymer degradation. Thus, a combined impact of abiotic and biotic factors promoted the oxidation/biodegradation of PE-LLD films containing pro-oxidants.
Robert E Prudhomme - One of the best experts on this subject based on the ideXlab platform.
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x ray pole figure and small angle scattering measurements on tubular bLown Low Density poly ethylene films
Macromolecules, 1996Co-Authors: Richard J Pazur, Robert E PrudhommeAbstract:Pole figures obtained by wide-angle X-ray diffraction have been used to quantify and characterize the molecular orientations induced in Low-Density poly(ethylene) films prepared by the tubular film process. Small-angle X-ray scattering was employed to determine the type and orientation of the morphology within the films. All films were found to possess a combination of two morphologies: a surface transcrystalline layer and a row-nucleated morphology caused by crystallization in Low-stress conditions. For the first series of bLown films, in which the draw-down ratio was increased from 1.9 to 7.9 for a constant bLow-up ratio of 1.68, the a axis was observed to increase its orientation along the extrusion direction, signifying that the row-nucleated structures intensify their orientation along this same direction. The amount of transcrystalline material decreases upon increasing the draw-down ratio. Unexpectedly, the amorphous regions tend to become biaxially oriented in the higher drawn samples. In the sec...
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x ray pole figure and small angle scattering measurements on tubular bLown Low Density poly ethylene films
Macromolecules, 1996Co-Authors: Richard J Pazur, Robert E PrudhommeAbstract:Pole figures obtained by wide-angle X-ray diffraction have been used to quantify and characterize the molecular orientations induced in Low-Density poly(ethylene) films prepared by the tubular film process. Small-angle X-ray scattering was employed to determine the type and orientation of the morphology within the films. All films were found to possess a combination of two morphologies : a surface transcrystalline layer and a row-nucleated morphology caused by crystallization in Low-stress conditions. For the first series of bLown films, in which the draw-down ratio was increased from 1.9 to 7.9 for a constant bLow-up ratio of 1.68, the a axis was observed to increase its orientation along the extrusion direction, signifying that the row-nucleated structures intensify their orientation along this same direction. The amount of transcrystalline material decreases upon increasing the draw-down ratio. Unexpectedly, the amorphous regions tend to become biaxially oriented in the higher drawn samples. In the second series of films, the bLow-up ratio was increased from 1.60 to 2.74 for a constant draw-down ratio of 4.2. In this case, the row-nucleated morphology became progressively oriented in the film plane upon bubble enlargement, thus creating an uniplanar orientation of the molecular chains in the film plane. The amorphous regions, weakly oriented on the onset along the extrusion direction, gradually become biaxially oriented in the film plane upon increasing the bLow-up ratio. Finally, it was shown that molecular orientation measurements can be used to verify the consistency of the processing conditions in bLown film production.
Andrea Corti - One of the best experts on this subject based on the ideXlab platform.
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oxidation and biodegradation of polyethylene films containing pro oxidant additives synergistic effects of sunlight exposure thermal aging and fungal biodegradation
Polymer Degradation and Stability, 2010Co-Authors: Andrea Corti, Sudhakar Muniyasamy, Manuele Vitali, Syed H Imam, Emo ChielliniAbstract:Abstract Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear Low Density poly(ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days during the summer months folLowed by their incubation with fungal strains previously isolated from the soil based on the ability to grow on the oxidized PE-LLD as a sole carbon source. Some films were also thermally aged at temperatures ranging between 45°C and 65 °C, either before or after fungal degradation. Films with pro-oxidant additives exhibited a higher level of oxidation as revealed by increase in their carbonyl index (CO i ). In addition to increase in the CO i , films showed a slight increase in crystallinity and melting temperature ( T m ), considerably Lower onset degradation temperatures, and a concomitant increase in the % weight of the residues. The level of oxidation observed in thermally aged films was directly proportional to the aging temperature. The PE-LLD films with pro-oxidant exposed to sunlight folLowed by thermal aging showed even higher rate and extent of oxidation when subsequently subjected to fungal biodegradation. The higher oxidation rate also correlated well with the CO 2 production in the fungal biodegradation tests. Similar films oxidized and aged but not exposed to fungal biodegradation showed much less degradation. Microscopic examination showed a profuse growth and colonization of fungal mycelia on the oxidized films by one strain, while another spore-producing strain grew around the film edges. Data presented here suggest that abiotic oxidation of polymer's carbon backbone produced metabolites which supported metabolic activities in fungal cells leading to further biotically-mediated polymer degradation. Thus, a combined impact of abiotic and biotic factors promoted the oxidation/biodegradation of PE-LLD films containing pro-oxidants.
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oxidation and biodegradation of polyethylene films containing pro oxidant additives synergistic effects of sunlight exposure thermal aging and fungal biodegradation
Polymer Degradation and Stability, 2010Co-Authors: Andrea Corti, Sudhakar Muniyasamy, Manuele Vitali, Syed H Imam, Emo ChielliniAbstract:Abstract Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear Low Density poly(ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days during the summer months folLowed by their incubation with fungal strains previously isolated from the soil based on the ability to grow on the oxidized PE-LLD as a sole carbon source. Some films were also thermally aged at temperatures ranging between 45°C and 65 °C, either before or after fungal degradation. Films with pro-oxidant additives exhibited a higher level of oxidation as revealed by increase in their carbonyl index (CO i ). In addition to increase in the CO i , films showed a slight increase in crystallinity and melting temperature ( T m ), considerably Lower onset degradation temperatures, and a concomitant increase in the % weight of the residues. The level of oxidation observed in thermally aged films was directly proportional to the aging temperature. The PE-LLD films with pro-oxidant exposed to sunlight folLowed by thermal aging showed even higher rate and extent of oxidation when subsequently subjected to fungal biodegradation. The higher oxidation rate also correlated well with the CO 2 production in the fungal biodegradation tests. Similar films oxidized and aged but not exposed to fungal biodegradation showed much less degradation. Microscopic examination showed a profuse growth and colonization of fungal mycelia on the oxidized films by one strain, while another spore-producing strain grew around the film edges. Data presented here suggest that abiotic oxidation of polymer's carbon backbone produced metabolites which supported metabolic activities in fungal cells leading to further biotically-mediated polymer degradation. Thus, a combined impact of abiotic and biotic factors promoted the oxidation/biodegradation of PE-LLD films containing pro-oxidants.
Richard J Pazur - One of the best experts on this subject based on the ideXlab platform.
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x ray pole figure and small angle scattering measurements on tubular bLown Low Density poly ethylene films
Macromolecules, 1996Co-Authors: Richard J Pazur, Robert E PrudhommeAbstract:Pole figures obtained by wide-angle X-ray diffraction have been used to quantify and characterize the molecular orientations induced in Low-Density poly(ethylene) films prepared by the tubular film process. Small-angle X-ray scattering was employed to determine the type and orientation of the morphology within the films. All films were found to possess a combination of two morphologies: a surface transcrystalline layer and a row-nucleated morphology caused by crystallization in Low-stress conditions. For the first series of bLown films, in which the draw-down ratio was increased from 1.9 to 7.9 for a constant bLow-up ratio of 1.68, the a axis was observed to increase its orientation along the extrusion direction, signifying that the row-nucleated structures intensify their orientation along this same direction. The amount of transcrystalline material decreases upon increasing the draw-down ratio. Unexpectedly, the amorphous regions tend to become biaxially oriented in the higher drawn samples. In the sec...
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x ray pole figure and small angle scattering measurements on tubular bLown Low Density poly ethylene films
Macromolecules, 1996Co-Authors: Richard J Pazur, Robert E PrudhommeAbstract:Pole figures obtained by wide-angle X-ray diffraction have been used to quantify and characterize the molecular orientations induced in Low-Density poly(ethylene) films prepared by the tubular film process. Small-angle X-ray scattering was employed to determine the type and orientation of the morphology within the films. All films were found to possess a combination of two morphologies : a surface transcrystalline layer and a row-nucleated morphology caused by crystallization in Low-stress conditions. For the first series of bLown films, in which the draw-down ratio was increased from 1.9 to 7.9 for a constant bLow-up ratio of 1.68, the a axis was observed to increase its orientation along the extrusion direction, signifying that the row-nucleated structures intensify their orientation along this same direction. The amount of transcrystalline material decreases upon increasing the draw-down ratio. Unexpectedly, the amorphous regions tend to become biaxially oriented in the higher drawn samples. In the second series of films, the bLow-up ratio was increased from 1.60 to 2.74 for a constant draw-down ratio of 4.2. In this case, the row-nucleated morphology became progressively oriented in the film plane upon bubble enlargement, thus creating an uniplanar orientation of the molecular chains in the film plane. The amorphous regions, weakly oriented on the onset along the extrusion direction, gradually become biaxially oriented in the film plane upon increasing the bLow-up ratio. Finally, it was shown that molecular orientation measurements can be used to verify the consistency of the processing conditions in bLown film production.
Syed H Imam - One of the best experts on this subject based on the ideXlab platform.
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oxidation and biodegradation of polyethylene films containing pro oxidant additives synergistic effects of sunlight exposure thermal aging and fungal biodegradation
Polymer Degradation and Stability, 2010Co-Authors: Andrea Corti, Sudhakar Muniyasamy, Manuele Vitali, Syed H Imam, Emo ChielliniAbstract:Abstract Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear Low Density poly(ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days during the summer months folLowed by their incubation with fungal strains previously isolated from the soil based on the ability to grow on the oxidized PE-LLD as a sole carbon source. Some films were also thermally aged at temperatures ranging between 45°C and 65 °C, either before or after fungal degradation. Films with pro-oxidant additives exhibited a higher level of oxidation as revealed by increase in their carbonyl index (CO i ). In addition to increase in the CO i , films showed a slight increase in crystallinity and melting temperature ( T m ), considerably Lower onset degradation temperatures, and a concomitant increase in the % weight of the residues. The level of oxidation observed in thermally aged films was directly proportional to the aging temperature. The PE-LLD films with pro-oxidant exposed to sunlight folLowed by thermal aging showed even higher rate and extent of oxidation when subsequently subjected to fungal biodegradation. The higher oxidation rate also correlated well with the CO 2 production in the fungal biodegradation tests. Similar films oxidized and aged but not exposed to fungal biodegradation showed much less degradation. Microscopic examination showed a profuse growth and colonization of fungal mycelia on the oxidized films by one strain, while another spore-producing strain grew around the film edges. Data presented here suggest that abiotic oxidation of polymer's carbon backbone produced metabolites which supported metabolic activities in fungal cells leading to further biotically-mediated polymer degradation. Thus, a combined impact of abiotic and biotic factors promoted the oxidation/biodegradation of PE-LLD films containing pro-oxidants.
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oxidation and biodegradation of polyethylene films containing pro oxidant additives synergistic effects of sunlight exposure thermal aging and fungal biodegradation
Polymer Degradation and Stability, 2010Co-Authors: Andrea Corti, Sudhakar Muniyasamy, Manuele Vitali, Syed H Imam, Emo ChielliniAbstract:Abstract Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear Low Density poly(ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days during the summer months folLowed by their incubation with fungal strains previously isolated from the soil based on the ability to grow on the oxidized PE-LLD as a sole carbon source. Some films were also thermally aged at temperatures ranging between 45°C and 65 °C, either before or after fungal degradation. Films with pro-oxidant additives exhibited a higher level of oxidation as revealed by increase in their carbonyl index (CO i ). In addition to increase in the CO i , films showed a slight increase in crystallinity and melting temperature ( T m ), considerably Lower onset degradation temperatures, and a concomitant increase in the % weight of the residues. The level of oxidation observed in thermally aged films was directly proportional to the aging temperature. The PE-LLD films with pro-oxidant exposed to sunlight folLowed by thermal aging showed even higher rate and extent of oxidation when subsequently subjected to fungal biodegradation. The higher oxidation rate also correlated well with the CO 2 production in the fungal biodegradation tests. Similar films oxidized and aged but not exposed to fungal biodegradation showed much less degradation. Microscopic examination showed a profuse growth and colonization of fungal mycelia on the oxidized films by one strain, while another spore-producing strain grew around the film edges. Data presented here suggest that abiotic oxidation of polymer's carbon backbone produced metabolites which supported metabolic activities in fungal cells leading to further biotically-mediated polymer degradation. Thus, a combined impact of abiotic and biotic factors promoted the oxidation/biodegradation of PE-LLD films containing pro-oxidants.
